Neural representation of the musical beat is facilitated but not contingent on the repetition of rhythmic patterns

Music often entails perception of periodic beats which serve as internal temporal references to coordinate movements to music. Crucially, beat perception arises even in syncopated musical rhythms, which only weakly cue the beat periodicity. However, syncopated rhythms are often looped in music, suggesting that repetition of rhythmic patterns may facilitate beat perception by providing a periodic structure at a supra-second timescale. Here, we tested this hypothesis by recording separately electroencephalographic (EEG) and behavioral responses (finger tapping) while participants listened to different syncopated rhythmic sequences. These sequences either consisted of a repeated pattern (repetition of 4.8 and 9.6-s-long patterns) or were generated without repetition. Despite the degradation of pattern repetition, neural activity showed a periodized representation of the rhythmic input across conditions, at periodicities corresponding to those expressed in behavioral responses. However, this neural activity was further enhanced in the condition with shorter repeated patterns. Thus, pattern repetition was not necessary but strengthened the neural representation of the beat, demonstrating that supra-second periodicities in the rhythmic input further enhance sub-second periodicities in neural activity. These findings highlight the multiscale temporal processing of musical rhythm, and, more generally, complex rhythmic inputs involved in interpersonal interaction and communication.